Energy source apparatus

ABSTRACT

A treatment system includes a treatment tool having a heater and bipolar electrodes to grip a treatment target. An energy source apparatus is used to electrically communicate with the treatment tool. The energy output source is configured to output high-frequency electric power to the bipolar electrodes through a first circuit. A high-frequency current flows through the treatment target between the bipolar electrodes. The energy output source is configured to output heater electric power to the heater for generating heat through a second circuit. At least one processor is used to control the energy output source.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of PCT Application No.PCT/JP 2017/009277 filed on Mar. 8, 2017, which is hereby incorporatedby reference in its entirety.

TECHNICAL FIELD

The technology disclosed herein relates generally to an energy sourceapparatus, and more particularly, some embodiments relate to an energysource apparatus for use with a treatment tool having bipolar electrodesand a heater.

DESCRIPTION OF THE RELATED ART

US Patent Application Pub. No. 2009/0248002A1 discloses a treatment toolcapable of gripping a treatment target such as a biotissue or the likebetween a pair of grippers and an energy source apparatus for supplyingthe treatment tool with electric energy. In the treatment tool, each ofthe grippers includes an electrode and at least one of the grippersincludes a heater. The energy source apparatus outputs high-frequencyelectric power to the electrodes, i.e., bipolar electrodes, and outputsheater electric power to the heater. Consequently, a high-frequencycurrent flows between the electrodes through the gripped treatmenttarget and heat generated by the heater is applied to the grippedtreatment target. In other words, both the high-frequency current andthe heater heat are applied to the treatment target.

According to US Patent Application Pub. No. 2009/0248002A1, the energysource apparatus detects the state of the treatment target using thehigh-frequency electric power. The energy source apparatus controls theoutput of the high-frequency electric power based on the detected stateof the treatment target. While both the high-frequency current and theheat are being applied to the treatment target, the heater heat maypossibly affect the detection of the state of the treatment target usingthe high-frequency electric power. If the heater heat affects thedetection of the state using the high-frequency electric power, then theheater heat also affects the control of the output of the high-frequencyelectric power based on the state of the treatment target.

BRIEF SUMMARY OF EMBODIMENTS

The disclosed technology has been made in view of the foregoing.

One aspect of the disclosed technology is directed a treatment systemthat comprises a treatment tool having a heater and bipolar electrodesto grip a treatment target. An energy source apparatus is used toelectrically communicate with the treatment tool. The energy outputsource is configured to output high-frequency electric power to thebipolar electrodes through a first circuit. A high-frequency currentflows through the treatment target between the bipolar electrodes. Theenergy output source is configured to output heater electric power tothe heater for generating heat through a second circuit. At least oneprocessor is used to control the energy output source. The at least oneprocessor is configured to control the heater for reaching a targettemperature while maintaining the heater at the target temperature. Theprocessor detects a parameter calculated based on the second circuitduring the process of controlling the heater for reaching the targettemperature. The processor sets a target value and/or a targettrajectory for outputting the high-frequency electric power based on theparameter while the treatment target is being modified by thehigh-frequency current applied thereto.

Another aspect of the disclosed technology is directed to a method ofoperating a treatment system having a treatment tool including a heaterand bipolar electrodes to grip a treatment target and an energy sourceapparatus used to electrically communicate with the treatment tool. Theenergy source apparatus comprises at least one processor used to controlthe energy output source by outputting high-frequency electric power tothe bipolar electrodes through a first circuit. A high-frequency currentis flowing through the treatment target between the bipolar electrodes.The energy output source is configured to output heater electric powerto the heater for generating heat through a second circuit. Next,controlling the heater for reaching a target temperature whilemaintaining the heater at the target temperature. Then, detecting aparameter calculated based on the second circuit during the process ofcontrolling the heater for reaching the target temperature. Finally,setting a target value and/or a target trajectory for outputting ahigh-frequency electric power based on the parameter.

BRIEF DESCRIPTION OF THE DRAWINGS

The technology disclosed herein, in accordance with one or more variousembodiments, is described in detail with reference to the followingfigures. The drawings are provided for purposes of illustration only andmerely depict typical or example embodiments of the disclosedtechnology. These drawings are provided to facilitate the reader'sunderstanding of the disclosed technology and shall not be consideredlimiting of the breadth, scope, or applicability thereof. It should benoted that for clarity and ease of illustration these drawings are notnecessarily made to scale.

FIG. 1 is a schematic view illustrating a treatment system according toa first embodiment.

FIG. 2 is a block diagram schematically illustrating an arrangement forsupplying electric energy from an energy source apparatus according tothe first embodiment to a treatment tool.

FIG. 3 is a flowchart of a processing sequence carried out by aprocessor of the energy source apparatus according to the firstembodiment.

FIG. 4 is a schematic diagram illustrating an example of chronologicalchanges in the temperature of a heater in the processing sequencecarried out by the processor according to the first embodiment.

FIG. 5 is a schematic diagram illustrating an example of chronologicalchanges in the heater electric power output from a heater power supplywhen the temperature of the heater changes chronologically asillustrated in FIG. 4 according to the first embodiment.

FIG. 6 is a schematic diagram illustrating an example of targettrajectories for an impedance set when the temperature of the heaterchanges chronologically as illustrated in FIG. 4 according to the firstembodiment.

FIG. 7 is a schematic diagram illustrating an example of chronologicalchanges in the high-frequency electric power output from ahigh-frequency power supply when the temperature of the heater changeschronologically as illustrated in FIG. 4 according to the firstembodiment.

FIG. 8 is a schematic diagram illustrating an example of voltage valuesof an output voltage set in a constant voltage control process forcontrolling the output from the high-frequency power supply when thetemperature of the heater changes chronologically as illustrated in FIG.4 according to a modification of the first embodiment.

FIG. 9A is a schematic diagram illustrating an example of targettrajectories set for the output voltage from the high-frequency powersupply when the temperature of the heater changes chronologically asillustrated in FIG. 4 according to another modification of the firstembodiment.

FIG. 9B is a schematic diagram illustrating an example of targettrajectories set for the output voltage from the high-frequency powersupply when the temperature of the heater changes chronologically asillustrated in FIG. 4 according to still another modification of thefirst embodiment.

FIG. 10 is a flowchart of a processing sequence carried out by aprocessor of an energy source apparatus according to a secondembodiment.

FIG. 11 is a schematic diagram illustrating an example of chronologicalchanges in the heater electric power output from a heater power supplyin the processing sequence carried out by the processor according to thesecond embodiment.

FIG. 12 is a schematic diagram illustrating an example, different fromthe example illustrated in FIG. 11, of chronological changes in theheater electric power output from the heater power supply in theprocessing sequence carried out by the processor according to the secondembodiment.

FIG. 13 is a schematic diagram illustrating an example of targettrajectories set for the output voltage from a high-frequency powersupply when the heater electric power changes chronologically asillustrated in FIG. 11 according to the second embodiment.

FIG. 14 is a schematic diagram illustrating an example of targettrajectories set for the output voltage from the high-frequency powersupply when the heater electric power changes chronologically asillustrated in FIG. 12 according to the second embodiment.

FIG. 15 is a schematic diagram illustrating an example of chronologicalchanges in the impedance of a treatment target in the processingsequence carried out by the processor according to the secondembodiment.

FIG. 16 is a schematic diagram illustrating an example of targettrajectories set for the output voltage from the high-frequency powersupply when the heater electric power changes chronologically asillustrated in FIG. 11 according to a modification of the secondembodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the following description, various embodiments of the technology willbe described. For purposes of explanation, specific configurations anddetails are set forth in order to provide a thorough understanding ofthe embodiments. However, it will also be apparent to one skilled in theart that the technology disclosed herein may be practiced without thespecific details. Furthermore, well-known features may be omitted orsimplified in order not to obscure the embodiment being described.

It is an object of the embodiment to provide an energy source apparatusthat appropriately detects the state of a treatment target even whileoutputting both high-frequency electric power and heater electric powerto a treatment tool, and appropriately controls the output of thehigh-frequency electric power based on the state of the treatmenttarget.

One aspect of the embodiment is directed to an energy source apparatushaving an end effector capable of gripping a treatment target between apair of grippers. The end effector is used with a treatment tool havinga heater and bipolar electrodes. The energy source apparatus includes anenergy output source that outputs high-frequency electric power to thebipolar electrodes thereby to cause a high-frequency current to flowthrough a treatment target between the bipolar electrodes. Moreover, theenergy output source outputs heater electric power to the heater therebyto cause the heater to generate heat. A processor performs an outputcontrol process on the output to the heater to cause the heater to reacha target temperature and to maintain the heater at the targettemperature. The processor detects a parameter related to thetemperature of the heater and the output to the heater in the outputcontrol process based on the target temperature, and sets at least oneof a target value and a target trajectory related to an output controlprocess for controlling the output to the bipolar electrodes while thetreatment target is being modified by the high-frequency current appliedthereto, based on the detected parameter.

First Embodiment

A first embodiment of the present disclosure will be described belowwith reference to FIGS. 1 through 7.

FIG. 1 is a view illustrating a treatment system 1 according to thepresent embodiment. As illustrated in FIG. 1, the treatment system 1includes a treatment tool 2 and an energy source apparatus 3 forsupplying the treatment tool 2 with electric energy. When the treatmenttool 2 is in use, the energy source apparatus 3 is used together withthe treatment tool 2. The treatment tool 2 includes a shaft 5 having alongitudinal axis C as its central axis. A housing 6 that can be held iscoupled to an end, i.e., proximal end, of the shaft 5 in a directionalong the longitudinal axis C. An end effector 7 is disposed on the endof the shaft 5 that is opposite to the end where the housing 6 ispositioned, i.e., on a distal end of the shaft 5. The housing 6 includesa grip 11 and a handle 12 mounted angularly movably thereon. When thehandle 12 is angularly moved with respect to the housing 6, the handle12 is opened or closed with respect to the grip 11.

The end effector 7 includes a pair of grippers 15 and 16. In thetreatment tool 2, a movable member 13 extends along the longitudinalaxis C inside or outside of the shaft 5. The movable member 13 has anend, i.e., distal end, connected to the end effector 7. The other end,i.e., proximal end, of the movable member 13 is coupled to the handle 12in the housing 6. When the handle 12 is opened or closed with respect tothe grip 11, the movable member 13 moves along the longitudinal axis Cof the shaft 5, opening or closing the grippers 15 and 16. The grippers15 and 16 are thus capable of gripping a biotissue such as a bloodvessel or the like as a treatment target therebetween. According to anembodiment, one of the grippers 15 and 16 is integral with or fixed tothe shaft 5, whereas the other of the grippers 15 and 16 is angularlymovably mounted on a distal end of the shaft 5. According to anotherembodiment, both the grippers 15 and 16 are angularly movably mounted onthe distal end of the shaft 5. According to an embodiment, an operatingmember, not illustrated, such as a rotary knob or the like, is mountedon the housing 6. When the operating member is rotated with respect tothe housing 6, the shaft 5 and the end effector 7 are rotated about thelongitudinal axis C with respect to the housing 6.

A cable 17 has an end connected to the housing 6. The other end of thecable 17 is separably connected to the energy source apparatus 3. Thetreatment system 1 includes a foot switch 18 as an operating memberseparate from the treatment tool 2. The foot switch 18 is electricallyconnected to the energy source apparatus 3. The foot switch 18 inputs anoperation for causing the energy source apparatus 3 to output electricenergy to the treatment tool 2. According to an embodiment, an operatingbutton or the like that is mounted as an operating member on the housing6 is included instead of or in addition to the foot switch 18. Theenergy source apparatus 3 outputs electric energy to the treatment tool2 in response to an operation entered through the operating member.

FIG. 2 is a diagram illustrating an arrangement for supplying electricenergy, i.e., high-frequency electric power P and heater electric powerP′ to be described hereinafter according to the present embodiment, fromthe energy source apparatus 3 to the treatment tool 2. As illustrated inFIG. 2, the treatment tool 2 includes an electrode 21 on the gripper 15and an electrode 22 on the gripper 16. The electrodes 21 and 22 arebipolar electrodes included in the end effector 7. The end effector 7includes a heater 23 as a heat generating element disposed on at leastone of the grippers 15 and 16.

The energy source apparatus 3 includes a processor, i.e., controller, 25and a storage medium 26. The processor 25 is in the form of anintegrated circuit or the like including a central processing unit(CPU), an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA), or the like. The energy source apparatus3 may include only one processor 25 or a plurality of processors 25. Theprocessor 25 carries out a processing sequence according to programsstored in the processor 25 or the storage medium 26. The storage medium26 stores processing programs used by the processor 25, parameters,functions, and tables used in operations performed by the processor 25,and so on. The processor 25 detects whether or not an operation isentered through the operating member such as the foot switch 18 or thelike.

The energy source apparatus 3 includes a high-frequency power supply 31as an energy output source. The high-frequency power supply 31 includesa waveform generator, a converting circuit, a transformer, and so on.The high-frequency power supply 31 converts electric power from abattery power supply, an outlet power supply, or the like intohigh-frequency electric power P. The high-frequency power supply 31 iselectrically connected to the electrode 21 on the gripper 15 through anelectric supply path 32. The high-frequency power supply 31 is alsoelectrically connected to the electrode 22 on the griper 16 through anelectric supply path 33. Each of the electric supply paths 32 and 33extends in the cable 17, the housing 6, and the shaft 5. Each of theelectric supply paths 32 and 33 is in the form of an electric wire orthe like. The high-frequency power supply 31 is capable of outputtingthe converted high-frequency electric power P. While the treatmenttarget is being gripped between the grippers 15 and 16, thehigh-frequency electric power P output from the high-frequency powersupply 31 is supplied through the electric supply paths 32 and 33 to theelectrodes 21 and 22. Therefore, a high-frequency current flows throughthe treatment target between the electrodes, i.e., bipolar electrodes 21and 22. At this time, the electrodes 21 and 22 have respectivepotentials that are different from each other. When a high-frequencycurrent having a certain magnitude is applied as treatment energy to thetreatment target, the treatment target is modified by the heat caused bythe high-frequency current. When an operation is entered through thefoot switch 18 or the like, the processor 25 controls the output fromthe high-frequency power supply 31 to the electrodes 21 and 22 in amanner to be described hereinafter.

The electric paths through which the high-frequency electric power P isoutput from the high-frequency power supply 31 to the electrodes 21 and22 include a current detecting circuit 35 and a voltage detectingcircuit 36. While the high-frequency electric power P is being outputfrom the high-frequency power supply 31, the current detecting circuit35 detects the current value of an output current I from thehigh-frequency power supply 31. At the same time, the voltage detectingcircuit 36 detects the voltage value of an output voltage V from thehigh-frequency power supply 31. An analog signal representing thecurrent value detected by the current detecting circuit 35 and an analogsignal representing the voltage value detected by the voltage detectingcircuit 36 are converted into digital signals by analog-digital (A/D)converters, not illustrated, or the like. The converted digital signalsare transmitted to the processor 25. The processor 25 now acquiresinformation regarding the output current I and the output voltage V fromthe high-frequency power supply 31. Based on the output current I andthe output voltage V that have been acquired, the processor 25 detectsimpedances of the electric paths through which the high-frequencyelectric power P is output from the high-frequency power supply 31 tothe electrodes 21 and 22. Based on the impedances of the electric pathsfor the high-frequency electric power P, the processor 25 detects animpedance Z of the gripped treatment target, i.e., a tissue impedance.Based on the output current I and the output voltage V that have beenacquired, the processor 25 also detects an electric power value of thehigh-frequency electric power P, i.e., an electric power value of theoutput electric power from the high-frequency power supply 31 to theelectrodes 21 and 22. The processor 25 controls the output from thehigh-frequency power supply 31 using the output current I and the outputvoltage V that have been acquired, and the impedance Z and thehigh-frequency electric power P that have been detected, in a manner tobe described hereinafter.

The energy source apparatus 3 includes a heater power supply 41 as anenergy output source. The heater power supply 41 includes a convertingcircuit, a transformer, and so on. The heater power supply 41 convertselectric power from a battery power supply, an outlet power supply, orthe like into heater electric power P′. The heater power supply 41 iselectrically connected to the heater 23 through electric supply paths 42and 43. Each of the electric supply paths 42 and 43 extends in the cable17, the housing 6, and the shaft 5. Each of the electric supply paths 42and 43 is in the form of an electric wire or the like. The heater powersupply 41 is capable of outputting the converted heater electric powerP′. The heater electric power P′ that is output is direct current (DC)electric power or alternate current (AC) electric power. When the heaterelectric power P′ output from the heater power supply 41 is suppliedthrough the electric supply paths 42 and 43 to the heater 23, the heater23 generates heat. While the treatment target is being gripped betweenthe grippers 15 and 16, the heat generated by the heater 23 is appliedto the treatment target. When a certain amount of heater heat is appliedas treatment energy to the treatment target, the treatment target ismodified. When an operation is entered through the foot switch 18 or thelike, the processor 25 controls the output from the heater power supply41 to the heater 23 in a manner to be described hereinafter.

The electric paths through which the heater electric power P′ is outputfrom the heater power supply 41 to the heater 23 include a currentdetecting circuit 45 and a voltage detecting circuit 46. While theheater electric power P′ is being output from the heater power supply41, the current detecting circuit 45 detects the current value of anoutput current I′ from the heater power supply 41. At the same time, thevoltage detecting circuit 46 detects the voltage value of an outputvoltage V′ from the heater power supply 41. An analog signalrepresenting the current value detected by the current detecting circuit45 and an analog signal representing the voltage value detected by thevoltage detecting circuit 46 are converted into digital signals by A/Dconverters, not illustrated, or the like. The converted digital signalsare transmitted to the processor 25. The processor 25 now acquiresinformation regarding the output current I′ and the output voltage V′from the heater power supply 41. Based on the output current I′ and theoutput voltage V′ that have been acquired, the processor 25 detectsimpedances of the electric paths through which the heater electric powerP′ is output from the heater power supply 41 to the heater 23. Based onthe impedances of the electric paths for the heater electric power P′,the processor 25 detects a resistance R of the heater 23. The resistanceR of the heater 23 varies depending on a temperature T of the heater 23.The storage medium 26 or the like stores a function, a table, or thelike that represents the relationship between the temperature T and theresistance R of the heater 23. Based on the detected resistance R andthe stored relationship between the temperature T and the resistance R,the processor 25 detects the temperature T of the heater 23. Based onthe output current I′ and the output voltage V′ that have been acquired,the processor 25 also detects an electric power value of the heaterelectric power P′, i.e., an electric power value of the output electricpower from the heater power supply 41 to the heater 23. The processor 25controls the output from the high-frequency power supply 31 and theoutput from the heater power supply 41 using the output current I′ andthe output voltage V′ that have been acquired and the temperature T,i.e., the resistance R, and the heater electric power P′ that have beendetected, in a manner to be described hereinafter.

Next, operation and advantages of the energy source apparatus 3 and thetreatment system 1 will be described below. For performing a treatmentusing the treatment system 1, the treatment tool 2 is connected throughthe cable 17 to the energy source apparatus 3. The surgeon holds thehousing 6 and inserts the end effector 7 into a body cavity such as anabdominal cavity or the like. While a treatment target such as abiotissue or the like is being positioned between the grippers 15 and16, the surgeon closes the handle 12 on the grip 11. The grippers 15 and16 are now closed, gripping the treatment target therebetween. When thesurgeon enters an operation through the operating member such as thefoot switch 18 or the like while the treatment target is being gripped,the output from the high-frequency power supply 31 to the electrodes 21and 22 and the output from the heater power supply 41 to the heater 23are controlled. When the high-frequency electric power P is supplied tothe electrodes 21 and 22, a high-frequency current flows through thetreatment target as described hereinbefore. When the heater electricpower P′ is supplied to the heater 23, heat generated by the heater 23is applied to the treatment target. The treatment target is treatingusing the high-frequency current and the heater heat as treatmentenergy.

FIG. 3 is a flowchart of a processing sequence carried out by theprocessor 25 of the energy source apparatus 3. As illustrated in FIG. 3,the processor 25 determines whether or not an operation is enteredthrough the operating member such as the foot switch 18 or the like,i.e., whether the entry of an operation is ON or OFF (S101). If anoperation is not entered (S101—No), then processing returns to S101. Inother words, the processor 25 waits until an operation is enteredthrough the operating member. If an operation is entered through theoperating member (S101—Yes), then the processor 25 starts to output thehigh-frequency electric power P from the high-frequency power supply 31to the electrodes 21 and 22 and also starts to output the heaterelectric power P′ from the heater power supply 41 to the heater 23.According to the present embodiment, when the high-frequency electricpower P starts to be output, the processor 25 outputs the high-frequencyelectric power P from the high-frequency power supply 31 at an electricpower value that is constant as a fixed value P0 (S102). At this time,the output current I and the output voltage V from the high-frequencypower supply 31 are adjusted to keep the electric power value of theoutput electric power from the high-frequency power supply 31 constantas the fixed value P0.

When the heater electric power P′ starts to be output from the heaterpower supply 41, the processor 25 performs aproportional-integral-derivative (PID) control process for a targettemperature T0 on the output from the heater power supply 41 to theheater 23 (S103). Specifically, an output control process is carried outon the output to the heater 23 for causing the temperature T of theheater 23 to reach the target temperature T0 while maintaining thetemperature T of the heater 23 at the target temperature T0. Accordingto the PID control process for the target temperature T0, the processor25 detects the resistance R of the heater 23 based on the output currentI′ and the output voltage V′ from the heater power supply 41 and detectsthe temperature T of the heater 23 based on the detected resistance R,as described hereinbefore. Then, the processor 25 adjusts the outputelectric power, i.e., the heater electric power P′, the output currentI′, and the output voltage V′ to the heater 23, based on the temperaturedeviation between the target temperature T0 and the temperature T of theheater 23, a time integral value of the temperature deviation, i.e., anintegrated value of the temperature deviation, and a time differentialvalue of the temperature deviation, i.e., a time rate of change of thetemperature deviation, causing the temperature T to reach the targettemperature T0 and maintaining the temperature T at the targettemperature T0. For example, if the temperature deviation between thetarget temperature T0 and the temperature T is large, then the processor25 causes the heater power supply 41 to output the heater electric powerP′ at a large electric power value. If the temperature deviation betweenthe target temperature T0 and the temperature T is small, and thetemperature deviation is zero, then the processor 25 causes the heaterpower supply 41 to output the heater electric power P′ at a smallelectric power value.

In an output control process for controlling the output from the heaterpower supply 41 to the heater 23 based on the target temperature T0, theprocessor 25 detects a chronological rate α of rise of the temperature Tup to the target temperature T0 as a parameter related to thetemperature T of the heater 23 (S104). The rate α of rise of thetemperature T varies depending on a tissue volume of the treatmenttarget including the thickness of a blood vessel, etc., the degree ofwetness of the treatment target, and so on. In other words, the rate αof rise, i.e., the speed of rise, varies depending on the state of thetreatment target including a thermal load on the treatment target. Thethermal load on the treatment target represents how difficult it is forthe temperature of the treatment target to rise. Providing identicalamounts of heat are applied to the treatment target, the temperature ofthe treatment target is more difficult to rise under a larger thermalload. The processor 25 sets a chronological rate β(α) of increase of theimpedance Z as a target value with respect to an output control processfor controlling the output from the high-frequency power supply 31 tothe electrodes 21 and 22, based on the rate α of rise detected as aparameter (S105). At this time, the rate β(α) of increase is calculatedusing the detected rate α of rise and a function or table, stored in thestorage medium 26 or the like, representing the relationship betweenrates α of rise of the temperature T and rates β of increase of theimpedance Z. The processor 25 sets a target trajectory for the impedanceZ as a target trajectory with respect to the output control process forcontrolling the output from the high-frequency power supply 31 (S106).At this time, the target trajectory is set such that the impedance Zincreases chronologically constantly at the set rate β(α) of increase.According to the present embodiment, the rate β(α) of increase of theimpedance Z is set such that the smaller the rate α of rise of thetemperature T is, the larger the rate β(α) of increase of the impedanceZ. Therefore, the smaller the rate α of rise of the temperature T, theprocessor 25 sets the gradient of the target trajectory for theimpedance Z to a larger value, and sets the value on the targettrajectory to a larger value at each point of time. After the rate α ofrise of the temperature T has been calculated and the rate β(α) ofincrease of the impedance Z and the target trajectory have been set, theprocessor 25 performs the above PID control process for the targettemperature T0 on the output from the heater power supply 41 to theheater 23 (S107).

When the rate α of rise of the temperature T is calculated and the rateβ(α) of increase of the impedance Z and the target trajectory are set,the processor 25 switches the output from the high-frequency powersupply 31 in a manner to have the impedance Z vary along the targettrajectory. In other words, the processor 25 controls the output of thehigh-frequency electric power P from the high-frequency power supply 31to the electrodes 21 and 22 in a manner to have the impedance Z varychronologically along the target trajectory for the set rate β(α) ofincrease (S108). At this time, the output electric power from thehigh-frequency power supply 31, i.e., the high-frequency electric powerP, the output current I, and the output voltage V are adjusted in amanner to have the impedance Z increase at a constant rate β(α) ofincrease. While the output of the high-frequency electric power P isbeing controlled based on the target trajectory for the impedance Z, thetreatment target is modified by the high-frequency current appliedthereto. If the high-frequency current is continuously applied to thetreatment target that has been dehydrated to a certain extent, then theimpedance Z increases chronologically due to the heat caused by thehigh-frequency current. According to the present embodiment, moreover,at a point of time upon elapse of a certain time from the start of theoutput control process for controlling the output from thehigh-frequency power supply 31 based on the target trajectory for theimpedance Z, the treatment target is dehydrated to a certain extent dueto the heater heat and the heat caused by the high-frequency current.Therefore, after the point of time upon elapse of the certain period oftime from the start of the output control process for controlling theoutput from the high-frequency power supply 31 based on the targettrajectory for the impedance Z, the impedance Z increaseschronologically due to the continuously applied high-frequency current.

While the output of the high-frequency electric power P is beingcontrolled based on the target trajectory for the impedance Z, theprocessor 25 detects whether or not an output time Q of thehigh-frequency electric power P is equal to or larger than a thresholdvalue Qth (S109). According to an embodiment, the output time Q isdetected from the time, used as a reference, when the output controlprocess for controlling the output from the high-frequency power supply31 based on the target trajectory for the impedance Z is started.According to another embodiment, the output time Q is detected from thetime, used as a reference, when the high-frequency electric power Pstarts to be output. In other words, the processor 25 detects the outputtime Q from a certain point of time, used as a reference, after thehigh-frequency power supply 31 starts to output the high-frequencyelectric power P. According to the present embodiment, the processor 25sets the threshold value Qth to a fixed value Qth0. If the output time Qof the high-frequency electric power P is shorter than the thresholdvalue Qth (S109-No), then processing goes back to step S107. Then, thesteps from S107 are successively carried out. Therefore, the processor25 continues the output from the high-frequency power supply 31 to theelectrodes, i.e., bipolar electrodes 21 and 22, continuously modifyingthe treatment target with the application of the high-frequency currentthereto. If the output time Q of the high-frequency electric power P isequal to or larger than the threshold value Qth (S109—Yes), then theprocessor 25 stops the output from the high-frequency power supply 31 tothe electrodes 21 and 22 (S110). At this time, the processor 25 may stopthe output from the heater power supply 41 to the heater 23 in responseto the stoppage of the output to the electrodes 21 and 22, or maycontinue the output from the heater power supply 41 to the heater 23. Ifthe output to the heater 23 is continued, then the processor 25 stopsthe output from the heater power supply 41 upon elapse of a certain timefrom the stoppage of the output to the electrodes 21 and 22 or based onan operation entered by the surgeon or the like. In case the output tothe heater 23 is continued, the processor 25 does not need to continuethe PID control process for the target temperature T0. For example, inresponse to the stoppage of the output to the electrodes 21 and 22, theprocessor 25 may control the output of the heater electric power P′ tothe heater 23 to lower the temperature T of the heater 23 to a targettemperature Ta0 lower than the target temperature T0 and maintain thetemperature T of the heater 23 at the target temperature Ta0. In thiscase, the target temperature Ta0 is set to a temperature low enough notto modify the treatment target, for example.

FIG. 4 illustrates an example of chronological changes in thetemperature T of the heater 23 in the processing sequence carried out bythe processor 25 as described hereinbefore. FIG. 5 illustrates anexample of chronological changes in the heater electric power P′ outputfrom the heater power supply 41 to the heater 23 when the temperature Tof the heater 23 changes chronologically as illustrated in FIG. 4. FIG.6 illustrates an example of target trajectories for the impedance Z setwhen the temperature T of the heater 23 changes chronologically asillustrated in FIG. 4. FIG. 7 illustrates an example of chronologicalchanges in the high-frequency electric power P output from thehigh-frequency power supply 31 to the electrodes 21 and 22 when thetemperature T of the heater 23 changes chronologically as illustrated inFIG. 4. In each of FIGS. 4 through 7, a horizontal axis represents timet from the start, used as a reference, of the output from the heaterpower supply 41. In FIG. 4, a vertical axis represents the temperature Tof the heater 23. In FIG. 5, a vertical axis represents the heaterelectric power P′. In FIG. 6, a vertical axis represents the impedance Zof the treatment target. In FIG. 7, a vertical axis represents thehigh-frequency electric power P. Each of FIGS. 4 through 7 illustratesthe chronological changes in three states, i.e., tissue states, X1through X3. The states X1 through X3 indicate thermal loads on thetreatment target that are different from each other due to the tissuevolume of the treatment target and/or the degree of wetness of thetreatment target. In the state X1, the tissue volume of the treatmenttarget is smaller because the blood vessel as the treatment target isthin, etc., and/or the treatment target is drier, than in the state X2.Therefore, the thermal load on the treatment target is smaller in thestate X1 than in the state X2. In the state X3, the tissue volume of thetreatment target is larger because the blood vessel as the treatmenttarget is thick, etc., and/or the treatment target is wetter, than inthe state X2. Therefore, the thermal load on the treatment target islarger in the state X3 than in the state X2. In each of FIGS. 4 through7, the chronological changes in the state X1 are indicated by thesolid-line curve, the chronological changes in the state X2 by thedot-and-dash-line curve, and the chronological changes in the state X3by the broken-line curve.

When the PID control process is performed on the output from the heaterpower supply 41 for the target temperature T0, as describedhereinbefore, the larger the thermal load on the treatment target, thesmaller the rate α of rise of the temperature T up to the targettemperature T0. In the examples illustrated in FIGS. 4 through 7,actually, the rate α1 of rise of the temperature T in the state X1 islarger than the rate α2 of rise of the temperature T in the state X2,and the rate α3 of rise of the temperature T in the state X3 is smallerthan the rate α2 of rise of the temperature T in the state X2.

When the PID control process is performed for the target temperature T0,until the temperature T becomes close to the target temperature T0 to acertain extent after the heater electric power P′ has started to beoutput, since the temperature deviation between the target temperatureT0 and the temperature T is large, the processor 25 increases the outputfrom the heater power supply 41. Consequently, the heater electric powerP′ increases chronologically until the temperature T becomes close tothe target temperature T0 to a certain extent. When the temperature Tbecomes close to the target temperature T0 to a certain extent, thetemperature deviation between the target temperature T0 and thetemperature T becomes small. It is also necessary to prevent thetemperature T from overshooting the target temperature T0. Therefore,when the temperature T becomes close to the target temperature T0 to acertain extent, the processor 25 reduces the output from the heaterpower supply 41. Consequently, when the temperature T becomes close tothe target temperature T0 to a certain extent, the heater electric powerP′ decreases chronologically. As the heater electric power P′ changeschronologically as described hereinbefore, until the temperature Treaches the target temperature T0 after the temperature T has becomeclose to the target temperature T0 to a certain extent, e.g.,immediately before the temperature T reaches the target temperature T0,the heater electric power P′ becomes peak electric power P′p. At thetime the heater electric power P′ has become the peak electric powerP′p, the heater electric power P′ switches from a chronologicallyincreasing state to a chronologically decreasing state.

When the PID control process is performed on the output from the heaterpower supply 41 for the target temperature T0, as describedhereinbefore, the larger the thermal load on the treatment target, thehigher the output from the heater power supply 41. Therefore, the largerthe thermal load on the treatment target, the larger the peak electricpower P′p of the heater electric power P. In the examples illustrated inFIGS. 4 through 7, actually, the peak electric power P′p1 of the heaterelectric power P′ in the state X1 is smaller than the peak electricpower P′p2 of the heater electric power P′ in the state X2, and the peakelectric power P′p3 of the heater electric power P′ in the state X3 islarger than the peak electric power P′p2 of the heater electric power P′in the state X2. Prior to the point of time at which the heater electricpower P′ has decreased from the peak electric power P′p to a certainextent, the larger the thermal load on the treatment target, the largeran integrated value W′ of the heater electric power P′ between twopoints of time, as is the case with the peak electric power P′p. Forexample, the larger the thermal load on the treatment target, the largerthe integrated value of the heater electric power P′ until it reachesthe peak electric power P′p after it has started to be output. Inasmuchas the larger the thermal load on the treatment target, the smaller therate α of rise of the temperature T, a time Y required for the heaterelectric power P′ to reach the peak electric power P′p after it hasstarted to be output is long. In the examples illustrated in FIGS. 4through 7, actually, a time Y1 required for the heater electric power P′to reach the peak electric power P′p1 in the state X1 is shorter than atime Y2 required for the heater electric power P′ to reach the peakelectric power P′p2 in the state X2, and a time Y3 required for theheater electric power P′ to reach the peak electric power P′p3 in thestate X3 is longer than the time Y2 required for the heater electricpower P′ to reach the peak electric power P′p2 in the state X2.

In case the thermal load on the treatment target is small because thetissue volume is small, etc., the temperature T of the heater 23 riseseven though the heater electric power P′ that is output is small to acertain degree. Therefore, in case the thermal load on the treatmenttarget is small, the heater electric power P′ increases gradually untilit reaches the peak electric power P′p immediately after it has startedto be output according to the PID control process for the targettemperature T0. Even after the heater electric power P′ has reached thepeak electric power P′p, the heater electric power P′ decreasesgradually. On the other hand, in case the thermal load on the treatmenttarget is large because the tissue volume is large, etc., it isdifficult for the temperature T of the heater 23 to rise unless theheater electric power P′ that is output is increased to a certainextent. Therefore, in case the thermal load on the treatment target islarge, the heater electric power P′ increases quickly until it reachesthe peak electric power P′p immediately after it has started to beoutput according to the PID control process for the target temperatureT0. After the heater electric power P′ has reached the peak electricpower P′p, the processor 25 quickly reduces the heater electric power P′in order to prevent the temperature T from overshooting the targettemperature T0. As the heater electric power P′ varies depending on thethermal load on the treatment target, as described hereinbefore, thelarger the thermal load on the treatment target, the larger a rate γ ofincrease of the heater electric power P′ up to the peak electric powerP′p. Furthermore, the larger the thermal load on the treatment target,the larger a rate ε of reduction of the heater electric power P′ afterhaving reached the peak electric power P′p. In the examples illustratedin FIGS. 4 through 7, actually, the rate γ1 of increase of the heaterelectric power P′ in the state X1 is smaller than the rate γ2 ofincrease of the heater electric power P′ in the state X2, and the rateγ3 of increase of the heater electric power P′ in the state X3 is largerthan the rate γ2 of increase of the heater electric power P′ in thestate X2. The rate ε1 of reduction of the heater electric power P′ inthe state X1 is smaller than the rate ε2 of reduction of the heaterelectric power P′ in the state X2, and the rate ε3 of reduction of theheater electric power P′ in the state X3 is larger than the rate ε2 ofreduction of the heater electric power P′ in the state X2.

Moreover, since the larger the thermal load on the treatment target, thelarger the rate α of rise of the temperature T, the processor 25 setsthe rate β of increase of the impedance Z as the target value withrespect to the output control process for controlling the output to theelectrodes 21 and 22, to a large value. Actually, the rate β(α1) ofincrease of the impedance Z set in the state X1 is smaller than the rateβ(α2) of increase of the impedance Z set in the state X2. The rate β(α3)of increase of the impedance Z set in the state X3 is larger than therate β(α2) of increase of the impedance Z set in the state X2.Furthermore, since the larger the thermal load on the treatment target,the larger the rate β of increase of the impedance Z is set, theprocessor 25 sets the value of the impedance Z on the target trajectoryat each point of time until the output of the high-frequency electricpower P is stopped, to a large value. Actually, at each point of timeuntil the output time Q of the high-frequency electric power P reachesthe threshold value Qth, i.e., Qth0 according to the present embodiment,the value on the target trajectory set in the state X1 is smaller thanthe value on the target trajectory set in the state X2. At each point oftime until the output time Q of the high-frequency electric power Preaches the threshold value Qth, the value on the target trajectory setin the state X3 is larger than the value on the target trajectory set inthe state X2. When the output of the high-frequency electric power P isstopped, i.e., when the output time Q reaches the threshold value Qth,the value Z1 of the impedance Z according to the target trajectory setin the state X1 is smaller than the value Z2 of the impedance Zaccording to the target trajectory set in the state X2. When the outputof the high-frequency electric power P is stopped, the value Z3 of theimpedance Z according to the target trajectory set in the state X3 issmaller than the value Z2 of the impedance Z according to the targettrajectory set in the state X2.

According to the present embodiment, as described hereinbefore, when therate α of rise of the temperature T is detected, the processor 25performs the output control process for controlling the output of thehigh-frequency electric power P based on the target trajectory where theimpedance Z increases chronologically at the set rate β of increase. Inthe output control process for controlling the output of thehigh-frequency electric power P based on the target trajectory for theimpedance Z, the larger the rate β of increase for the impedance Z, thelarger the high-frequency electric power P that is output. According tothe present embodiment, inasmuch as the larger the thermal load on thetreatment target, the larger the rate β of increase of the impedance Zis set, the high-frequency electric power P that is output is large.Therefore, In the output control process for controlling the output ofthe high-frequency electric power P based on the target trajectory forthe impedance Z, the larger the thermal load on the treatment target,the larger the high-frequency current flowing through the treatmenttarget. In the examples illustrated in FIGS. 4 through 7, actually, inthe output control process for controlling the output of thehigh-frequency electric power P based on the target trajectory for theimpedance Z, the high-frequency electric power P that is output issmaller in the state X1 than in the state X2, and the high-frequencyelectric power P that is output is larger in the state X3 than in thestate X2. In the output control process for controlling the output ofthe high-frequency electric power P based on the target trajectory forthe impedance Z, the high-frequency electric power P that is outputincreases chronologically while the impedance Z is being low. When theimpedance Z rises to a certain extent, the high-frequency electric powerP that is output switches from a chronologically increasing state to achronologically decreasing state. Until the output of the high-frequencyelectric power P is stopped, the high-frequency electric power Pdecreases chronologically. In the examples illustrated in FIGS. 4through 7, before the rate α of rise is detected, the output from thehigh-frequency power supply 31 is controlled to keep the electric powervalue of the high-frequency electric power P constant as the fixed valueP0 in either one of the states X1 through X3.

According to the present embodiment, as described hereinbefore, thecontrol process for controlling the output to the heater 23 is carriedout to cause the heater 23 to reach the target temperature T0 and tokeep the heater 23 at the target temperature T0. In the control processbased on the target temperature T0, the rate α of rise until thetemperature T reaches the target temperature T0 is detected as aparameter related to the temperature T of the heater 23. Since the rateα of rise of the temperature T varies depending on the tissue volume andthe degree of wetness of the treatment target, as describedhereinbefore, the rate α of rise of the temperature T varies dependingon the state of the treatment target including the thermal load on thetreatment target. Consequently, even while the treatment tool 2 is beingsupplied with both the high-frequency electric power P and the heaterelectric power P′, the state of the treatment tool can appropriately bedetected by detecting the rate α of rise.

According to the present embodiment, furthermore, in the output controlprocess for controlling the output from the high-frequency power supply31 while the treatment target is being modified by the high-frequencycurrent, the rate β(α) of increase of the impedance Z as a target valueand the target trajectory for the impedance Z are set based on thedetected rate α of rise of the temperature T. Since the rate β(α) ofincrease of the impedance Z and the target trajectory for the impedanceZ are set based on the rate α of rise, the rate β(α) of increase is setto an appropriate value corresponding to the state of the treatmenttarget, and the target trajectory for the impedance Z is set to anappropriate trajectory corresponding to the state of the treatmenttarget. By controlling the output of the high-frequency electric power Pbased on the rate β(α) of increase of the impedance Z and the targettrajectory that have been set, therefore, the high-frequency powersupply 31 outputs the high-frequency electric power P appropriatelydepending on the state of the treatment target, appropriately applyingthe high-frequency current to the treatment target depending on thestate of the treatment target. According to the present embodiment,therefore, even while the treatment tool 2 is being supplied with boththe high-frequency electric power P and the heater electric power P′,the output of the high-frequency electric power P is appropriatelycontrolled based on the state of the treatment target.

Modifications of the First Embodiment

According to the first embodiment, in the output control process forcontrolling the output from the heater power supply 41 based on thetarget temperature T0, the rate α of rise of the temperature T isdetected, and the rate β of increase of the impedance Z and the targettrajectory for the impedance Z, which are target values with respect tothe output control process for controlling the output to the electrodes21 and 22, are set based on the detected rate α of rise. However, thepresent disclosure is not limited to such details. According to amodification, in the output control process for controlling the outputfrom the heater power supply 41 based on the target temperature T0, theprocessor 25 detects either one of the peak electric power P′p of theheater electric power P′, the time Y required for the heater electricpower P′ to reach the peak electric power P′p, the rate γ of increase ofthe heater electric power P′ up to the peak electric power P′p, the rateof reduction of the heater electric power P′ after having reached thepeak electric power P′p, and the integrated value W′ of the heaterelectric power P′ as a parameter related to the output to the heater 23,instead of carrying out the processing of step S104 for detecting therate α of rise of the temperature T. The integrated value W′ of theheater electric power P′ may be either one of an integrated valuebetween two points of time until the peak electric power P′p is reached,an integrated value between two points of time including the peakelectric power P′p, and an integrated value between two points of timeafter the peak electric power P′p has been reached. The processor 25then sets the rate β of increase of the impedance Z as a target valuerelated to the output control process for controlling the output fromthe high-frequency power supply 31 to the electrodes 21 and 22, based onthe above parameter, i.e., either one of P′p, Y, γ, ε, and W′, relatedto the detected output to the heater 23, instead of carrying out theprocessing of step S105. Then, in the same manner as the processing ofstep S106, the processor 25 sets the target trajectory for the impedanceZ as a target trajectory related to the output control process forcontrolling the output from the high-frequency power supply 31 to theelectrodes 21 and 22, based on the set rate β of increase of theimpedance Z.

As described hereinbefore, since each of the peak electric power P′p,the reaching time Y, the rate γ of increase, the rate ε of reduction,and the integrated value W′ varies depending on the tissue volume of thetreatment target, the degree of wetness of the treatment target, etc.,ease of those parameters varies depending on the state of the treatmenttarget including the thermal load on the treatment target. However, asdescribed hereinbefore, the larger the thermal load on the treatmenttarget, the larger each of the parameters, i.e., P′p, Y, γ, ε, and W′.According to the present modification, therefore, the larger theparameter, i.e., either one of P′p, Y, γ, ε, and W′, related to thedetected output to the heater 23, the processor 25 sets the rate β ofincrease of the impedance Z to a larger value. Consequently, the largerthe parameter, i.e., either one of P′p, Y, γ, ε, and W′, related to thedetected output to the heater 23, the processor 25 sets the gradient ofthe target trajectory for the impedance Z to a larger value, and setsthe value on the target trajectory for the impedance Z to a larger valueat each point of time.

According to the present modification, by detecting the parameter, i.e.,either one of P′p, Y, γ, ε, and W′, related to the output to the heater23, the state of the treatment target is appropriately detected evenwhile the treatment tool 2 is being supplied with both thehigh-frequency electric power P and the heater electric power P′.Furthermore, as the rate β of increase of the impedance Z and the targettrajectory for the impedance Z are set based on the parameter, i.e.,either one of P′p, Y, γ, ε, and W′, the rate β of increase is set to anappropriate value corresponding to the state of the treatment target,and the target trajectory for the impedance Z is set to an appropriatetrajectory corresponding to the state of the treatment target. Thus, bycontrolling the output of the high-frequency electric power P based onthe set rate β of increase of the impedance Z and the set targettrajectory for the impedance Z, the high-frequency electric power P isappropriately output by the high-frequency power supply 31 depending onthe state of the treatment target, and the high-frequency current isappropriately applied to the treatment target depending on the state ofthe treatment target. According to the present modification, therefore,while the treatment tool 2 is being supplied with both thehigh-frequency electric power P and the heater electric power P′, theoutput of the high-frequency electric power P is appropriatelycontrolled based on the state of the treatment target.

According to a modification, in the output control process forcontrolling the output from the heater power supply 41 based on thetarget temperature T0, the processor 25 detects the parameter, i.e., a,related to the temperature T of the heater 23 and a plurality of ones ofthe parameters, i.e., P′p, Y, γ, ε, and W′, related to the output to theheater 23. Then, the processor 25 sets the rate β of increase of theimpedance Z and the target trajectory for the impedance Z, which aretarget values with respect to the output control process for controllingthe output from the high-frequency power supply 31 to the electrodes 21and 22, based on the detected parameters, i.e., two or more of α, P′p,Y, γ, ε, and W′.

According to a modification, the processor 25 sets the rate β ofincrease of the impedance Z and the target trajectory for the impedanceZ based on the impedance Z before the parameter, i.e., either one of α,P′p, Y, γ, ε, and W′, is detected, in addition to the parameter, i.e.,either one of α, P′p, Y, γ, ε, and W′. According to the presentmodification, the processor 25 detects the impedance Z based on theoutput from the high-frequency power supply 31 before the parameter,i.e., either one of α, P′p, Y, γ, ε, and W′, is detected. At this time,the processor 25 detects an initial value Ze of the impedance Z at thesame time as or immediately after the start of the output from thehigh-frequency power supply 31, and/or a chronological change of theimpedance Z from the initial value Ze until the parameter, i.e., eitherone of α, P′p, Y, γ, ε, and W′, is detected. When the rate β of increaseof the impedance Z and the target trajectory for the impedance Z are tobe set based on the rate α of rise of the temperature T and thechronological change of the impedance Z, for example, the rate β ofincrease of the impedance Z and the target trajectory for the impedanceZ that are to be set are different if the impedance varies differentlybefore the parameter, i.e., either one of α, P′p, Y, γ, ε, and W′, isdetected even though the rate α of rise remains the same.

According to the embodiment described hereinbefore, etc., the outputcontrol process for controlling the output from the high-frequency powersupply 31 based on the target trajectory for the impedance Z is carriedout after the parameter, i.e., either one of α, P′p, Y, γ, ε, and W′, isdetected. However, the present disclosure is not limited to suchdetails. According to a modification, when the parameter, i.e., eitherone of α, P′p, Y, γ, ε, and W′, is detected, the processor 25 carriesout a constant voltage control process for keeping the output voltage Vat a constant voltage value Va with respect to the output from thehigh-frequency power supply 31, instead of carrying out the processingof step S108. According to the present modification, the processor 25sets the voltage value Va of the output voltage V as a target value withrespect to the constant voltage control process for controlling theoutput from the high-frequency power supply 31, based on the detectedparameter, i.e., either one of α, P′p, Y, γ, ε, and W′, instead ofcarrying out the processing of steps S105 and S106. At this time, thelarger the thermal load on the treatment target, the processor 25 setsthe voltage value Va to a larger value. For example, if the rate α ofrise of the temperature T is to be detected as a parameter related tothe temperature T, then the smaller the rate α of rise, the processor 25sets the voltage value Va as a target value to a larger value. If thepeak electric power P′p of the heater electric power P′ is to bedetected as a parameter related to the output to the heater 23, then thelarger the peak electric power P′p, the processor 25 sets the voltagevalue Va to a larger value.

FIG. 8 illustrates an example of voltage values Va of the output voltageV set in the constant voltage control process for controlling the outputfrom the high-frequency power supply 31 when the temperature T of theheater 23 changes chronologically as illustrated in FIG. 4, i.e., whenthe heater electric power P′ output to the heater 23 changeschronologically as illustrated in FIG. 5, according to the presentmodification. In FIG. 8, a horizontal axis represents time t from thestart, used as a reference, of the output from the heater power supply41, and a vertical axis the output voltage V from the high-frequencypower supply 31. FIG. 8 illustrates voltages Va set as target values forthe three states, i.e., tissue states, X1 through X3. In FIG. 8, thevoltage Va for the state X1 is indicated by the solid-line curve, thevoltage Va for the state X2 by the dot-and-dash-line curve, and thevoltage Va for the state X3 by the broken-line curve. Since the thermalload on the treatment target is smaller in the state X1 than in thestate X2, as described hereinbefore, the voltage value Va1 set in theconstant voltage control process for the state X1 is smaller than thevoltage value Va2 set in the constant voltage control process for thestate X2. Moreover, since the thermal load on the treatment target islarger in the state X3 than in the state X2, the voltage value Va3 setin the constant voltage control process for the state X3 is larger thanthe voltage value Va2 set in the constant voltage control process forthe state X2.

According to the present modification, inasmuch as the voltage value Vaof the output voltage V from the high-frequency power supply 31 in theconstant voltage control process is set based on the parameter, i.e.,either one of α, P′p, Y, γ, ε, and W′, the voltage value Va is set to anappropriate value corresponding to the state of the treatment target.Accordingly, since the constant voltage control process is performed onthe output from high-frequency power supply 31 based on the voltagevalue Va set as a target value, the appropriate output is produced fromthe high-frequency power supply 31 depending on the state of thetreatment target, applying the appropriate high-frequency current to thetreatment target depending on the state of the treatment target, alsoaccording to the present modification. According to the presentmodification, therefore, while the treatment tool 2 is being suppliedwith both the high-frequency electric power P and the heater electricpower P′, the output from the high-frequency power supply 31 isappropriately controlled based on the state of the treatment target.

According to a modification, the processor 25 performs, on the outputfrom the high-frequency power supply 31, a constant power controlprocess for keeping the output electric power from the high-frequencypower supply 31, i.e., the high-frequency electric power P, at aconstant electric power value Pa, or a constant current control processfor keeping the output current I therefrom at a constant current valueIa, rather than performing the constant voltage control processdescribed hereinbefore. For performing the constant power controlprocess, the processor 25 sets the electric power value Pa based on thedetected parameter, i.e., either one of α, P′p, Y, γ, ε, and W′. At thistime, the larger the thermal load on the treatment target, the processor25 sets the electric power value Pa to a larger value. Similarly, forperforming the constant current control process, the processor 25 setsthe current value Ia based on the detected parameter, i.e., either oneof α, P′p, Y, γ, ε, and W′. At this time, the larger the thermal load onthe treatment target, the processor 25 sets the current value Ia to alarger value. When either one of the constant voltage control process,the constant power control process, and the constant current controlprocess is performed, at a point of time upon elapse of a certain timefrom the start of either one of the constant voltage control process,the constant power control process, and the constant current controlprocess described hereinbefore, the treatment target is dehydrated to acertain extent. Therefore, after the point of time upon elapse of thecertain period of time from the start of either one of the constantvoltage control process, the constant power control process, and theconstant current control process, the impedance Z increaseschronologically due to the continuously applied high-frequency current.

According to a modification, after the parameter, i.e., either one of α,P′p, Y, γ, ε, and W′, has been detected, the processor 25 switchesbetween the constant voltage control process, the constant power controlprocess, and the constant current control process based on the impedanceZ. In this case, the processor 25 switches between the constant voltagecontrol process, the constant power control process, and the constantcurrent control process based on a switching valve Zs1 and a switchingvalue Zs2 larger than the switching value Zs1. For example, if theimpedance Z is smaller than the switching value Zs1, then the processor25 carries out the above constant current control process on the outputfrom the high-frequency power supply 31. If the impedance Z is equal toor larger than the switching value Zs1 and smaller than the switchingvalue Zs2, then the processor 25 carries out the above constant powercontrol process on the output from the high-frequency power supply 31.If the impedance Z is equal to or larger than the switching value Zs2,then the processor 25 carries out the above constant voltage controlprocess on the output from the high-frequency power supply 31. Accordingto the present modification, as described hereinbefore, the voltagevalue Va for the constant voltage control process, the electric powervalue Pa for the constant power control process, and the current valueIa for the constant current control process are set based on thedetected parameter, i.e., either one of α, P′p, Y, γ, ε, and W′.Therefore, the larger the thermal load on the treatment target, theprocessor 25 sets each of the voltage value Va, the electric power valuePa, and the current value Ia to a larger value.

According to a modification, the processor 25 sets a chronological rateηa of increase, i.e., rate of change, of the output voltage V as atarget value for the output control process for controlling the outputfrom the high-frequency power supply 31 based on the detected parameter,i.e., either one of α, P′p, Y, γ, ε, and W′, instead of performing theprocessing of S105. Then, the processor 25 sets a target trajectory forthe set output voltage V for the output control process for controllingthe output from the high-frequency power supply 31 based on the set rateηa of increase of the output voltage V, instead of performing theprocessing of S106. According to the set target trajectory, the outputvoltage V increases chronologically constantly at the set rate ηa ofincrease. Then, the processor 25 controls the output from thehigh-frequency power supply 31 to cause the output voltage V to changealong the target trajectory, instead of performing the processing ofS108. According to the present modification, the larger the thermal loadon the treatment target, the processor 25 sets the rate ηa of increaseas a target value to a larger value. Therefore, the larger the thermalload on the treatment target, the processor 25 sets the gradient of thetarget trajectory for the output voltage V to a larger value, and setsthe value of the output voltage V on the target trajectory to a largervalue at each point of time.

FIG. 9A illustrates an example of target trajectories set for the outputvoltage V from the high-frequency power supply 31 when the temperature Tof the heater 23 changes chronologically as illustrated in FIG. 4, i.e.,when the heater electric power P′ output to the heater 23 changeschronologically as illustrated in FIG. 5, according to the presentmodification. In FIG. 9A, a horizontal axis represents time t from thestart, used as a reference, of the output from the heater power supply41, and a vertical axis the output voltage V from the high-frequencypower supply 31. FIG. 9A illustrates the target trajectories in theabove three states, i.e., tissue states, X1 through X3. In FIG. 9A, thetarget trajectory in the state X1 is indicated by the solid-line curve,the target trajectory in the state X2 by the dot-and-dash-line curve,and the target trajectory in the state X3 by the broken-line curve. Asdescribed hereinbefore, since the thermal load on the treatment targetis smaller in the state X1 than in the state X2, the rate real ofincrease of the output voltage V set in the state X1 is smaller than therate ηa2 of increase of the output voltage V set in the state X2.Therefore, at each point of time until the output time Q of thehigh-frequency electric power P reaches the threshold value Qth, i.e.,Qth0 according to the present modification, the value on the targettrajectory set in the state X1 is smaller than the value on the targettrajectory set in the state X2. Furthermore, since the thermal load onthe treatment target is larger in the state X3 than in the state X2, therate ηa3 of increase of the output voltage V set in the state X3 islarger than the rate ηa2 of increase of the output voltage V set in thestate X2. Therefore, at each point of time until the output time Q ofthe high-frequency electric power P reaches the threshold value Qth, thevalue on the target trajectory set in the state X3 is larger than thevalue on the target trajectory set in the state X2.

According to the present modification, as the rate ηa of increase of theoutput voltage V as a target value and the target trajectory for theoutput voltage V are set based on the parameter, i.e., either one of α,P′p, Y, γ, ε, and W′, the rate ηa of increase is set to an appropriatevalue corresponding to the state of the treatment target and the targettrajectory for the output voltage V is set to an appropriate trajectorycorresponding to the state of the treatment target. Consequently, whenthe output from the high-frequency power supply 31 is controlled basedon the set rate ηa of increase of the output voltage V and the settarget trajectory, the appropriate output is produced from thehigh-frequency power supply 31 depending on the state of the treatmenttarget, applying the appropriate high-frequency current to the treatmenttarget depending on the state of the treatment target, also according tothe present modification.

According to a modification, the processor 25 sets a chronological rateηa of increase, i.e., rate of change, of the output voltage V accordingto the target trajectory to a fixed value ηa0 regardless of the detectedparameter, i.e., either one of α, P′p, Y, γ, ε, and W′. Therefore, thegradient of the target trajectory for the output voltage V does not varydepending on the parameter, i.e., either one of α, P′p, Y, γ, ε, and W′.Here, there is defined a value, i.e., a starting point value, Vst of theoutput voltage V at the starting point of the target trajectory upon thestart of the output from the high-frequency power supply 31 based on thetarget trajectory. According to the present modification, the processor25 sets the value Vst of the output voltage V at the starting point ofthe target trajectory as a target value for the output control processfor controlling the output from the high-frequency power supply 31,based on the detected parameter, i.e., either one of α, P′p, Y, γ, ε,and W′, instead of carrying out the processing of step S105. Then, theprocessor 25 sets the target trajectory for the output voltage V in theoutput control process for controlling the output from thehigh-frequency power supply 31, based on the set starting point valueVst of the output voltage V, instead of carrying out the processing ofstep S106. According to the set target trajectory, the output voltage Vincreases chronologically constantly at the fixed value ηa0 from the setstarting point value Vst. Then, the processor 25 controls the outputfrom the high-frequency power supply 31 in a manner to have the outputvoltage V vary along the target trajectory, instead of carrying out theprocessing of step S108. According to the present modification, thelarger the thermal load on the treatment target, the processor 25 setsthe starting point value Vst as a target value to a larger value.Consequently, also according to the present modification, the larger thethermal load on the treatment target, the processor 25 sets the value ofthe output voltage V on the target trajectory to a larger value at eachpoint of time.

FIG. 9B illustrates an example of target trajectories set for the outputvoltage V from the high-frequency power supply 31 when the temperature Tof the heater 23 changes chronologically as illustrated in FIG. 4according to the present modification. In FIG. 9B, a horizontal axisrepresents time t from the start, used as a reference, of the outputfrom the heater power supply 41, and a vertical axis the output voltageV from the high-frequency power supply 31. FIG. 9B illustrates thetarget trajectories in the above three states, i.e., tissue states, X1through X3. In FIG. 9B, the target trajectory in the state X1 isindicated by the solid-line curve, the target trajectory in the state X2by the dot-and-dash-line curve, and the target trajectory in the stateX3 by the broken-line curve. As described hereinbefore, since thethermal load on the treatment target is smaller in the state X1 than inthe state X2, the value Vst1 of the output voltage V at the startingpoint of the target trajectory set in the state X1 is smaller than thevalue Vst2 of the output voltage V at the starting point of the targettrajectory set in the state X2. Therefore, at each point of time untilthe output time Q of the high-frequency electric power P reaches thethreshold value Qth, i.e., Qth0 according to the present modification,the value on the target trajectory set in the state X1 is smaller thanthe value on the target trajectory set in the state X2. Furthermore,since the thermal load on the treatment target is larger in the state X3than in the state X2, the value Vst3 of the output voltage V at thestarting point of the target trajectory set in the state X3 is largerthan the value, i.e., the starting point value, Vst2 of the outputvoltage V at the starting point of the target trajectory set in thestate X2. Therefore, at each point of time until the output time Q ofthe high-frequency electric power P reaches the threshold value Qth, thevalue on the target trajectory set in the state X3 is larger than thevalue on the target trajectory set in the state X2. According to anothermodification, the processor 25 sets both the rate ηa of increase of theoutput voltage V and the starting point value Vst of the output voltageV at the starting point of the target trajectory as target values, basedon the detected parameter, i.e., either one of α, P′p, Y, γ, ε, and W′.Also in this case, the larger the thermal load on the treatment target,the processor 25 sets the rate ηa of increase to a larger value and setsthe gradient of the target trajectory for the output voltage V to alarger value. Moreover, the larger the thermal load on the treatmenttarget, the processor 25 sets the starting point value Vst of the outputvoltage V at the starting point of the target trajectory to a largervalue.

Second Embodiment

A second embodiment of the present disclosure will be described belowwith reference to FIGS. 10 through 15. According to the secondembodiment, the processing according to the first embodiment is modifiedas described below. Those parts of the second embodiment which areidentical to those of the first embodiment are denoted by identicalnumeral reference, and will not be described below.

FIG. 10 is a flowchart of a processing sequence carried out by aprocessor 25 of an energy source apparatus 3 according to the presentembodiment. According to the present embodiment, as illustrated in FIG.10, the processor 25 determines whether or not an operation is enteredthrough an operating member such as a foot switch 18 or the like (S111).If an operation is entered (S111—Yes), then the processor 25 causes thehigh-frequency power supply 31 to output the high-frequency electricpower P at a constant electric power value P0 (S112), and performs a PIDcontrol process on the output from the heater power supply 41 (S113), aswith the embodiment described hereinbefore, etc. According to thepresent embodiment, the processor 25 determines whether or not time tfrom the start, used as a reference, of the output from the heater powersupply 41 is equal to or larger than time ta at a first point of time(S114). If time t is shorter than time ta (S114—No), then processinggoes back to step S112. Then, the steps from S112 are successivelycarried out. In other words, up to the first point of time (ta), theprocessor 25 causes the high-frequency power supply 31 to output thehigh-frequency electric power P at the electric power value P0, andperforms the PID control process for the target temperature T0 on theoutput from the heater power supply 41.

If time t is equal to or larger than time ta (S114—Yes), then theprocessor 25 detects an integrated value W′a of the heater electricpower P′ from the start of the output from the heater power supply 41 tothe first point of time (ta) as a parameter related to the output to theheater 23 (S115). According to the present embodiment, the integratedvalue W′ a is used as a first parameter detected at the first point oftime (ta). As described hereinbefore, the integrated value W′a variesdepending on the state of the treatment target including the thermalload on the treatment target. Now, there is defined a second point oftime (tb) subsequent to the first point of time (ta). According to thepresent embodiment, each of times ta and tb is of a fixed value.According to the present embodiment, the processor 25 sets a rate ηb ofchronological change, i.e., a rate of increase according to the presentembodiment, of the output voltage V as a target value related to theoutput control process for controlling the output from thehigh-frequency power supply 31 to the electrodes 21 and 22 from thefirst point of time (ta) to the second point of time (tb), based on theintegrated value W′a detected as the first parameter (S116). Moreover,the processor 25 sets a target trajectory for the output voltage V inthe output control process for controlling the output to the electrodes21 and 22 from the first point of time (ta) to the second point of time(tb), based on the set rate ηb of change (S116). At this time, thetarget trajectory is set such that the output voltage V increaseschronologically constantly at the set rate ηb of change. According tothe present embodiment, the larger the integrated value W′ of the heaterelectric power P′, the processor 25 sets the rate ηb of change of theoutput voltage V to a larger value. Consequently, the larger theintegrated value, i.e., the first parameter, W′a, the processor 25 setsthe value on the trajectory value at each point of time from the firstpoint of time (ta) to the second point of time (tb) to a larger value.

Even after the integrated value W′a has been calculated and the rate ηbof change of the output voltage V and the target trajectory have beenset, the processor 25 performs the above PID control process for thetarget temperature T0 on the output from the heater power supply 41 tothe heater 23 (S117). After the rate ηb of change of the output voltageV and the target trajectory have been set, the processor 25 controls theoutput to the electrodes 21 and 22 in a manner to have the outputvoltage V vary chronologically along the target trajectory for the setrate ηb of change (S118). At this time, the treatment target is modifiedby the high-frequency current applied thereto. According to the presentembodiment, the processor 25 determines whether or not time t is equalto or larger than time tb at the second point of time (S119). If time tis shorter than time tb (S119—No), then processing goes back to S117.Then, the steps from S117 are successively carried out. In other words,up to the second point of time (tb), the processor 25 carries out theoutput control process on the output from the high-frequency powersupply 31 based on the target trajectory for the output voltage V, andcarries out the PID control process for the target temperature T0 on theoutput from the heater power supply 41.

If time t is equal to or larger than time tb (S119—Yes), then theprocessor 25 detects an integrated value W′b of the heater electricpower P′ from the first point of time (ta) to the second point of time(tb) as a parameter related to the output to the heater 23 (S120).According to the present embodiment, the integrated value W′b is used asa second parameter detected at the second point of time (tb). Asdescribed hereinbefore, the integrated value W′b varies depending on thestate of the treatment target including the thermal load on thetreatment target. According to the present embodiment, the processor 25sets a voltage value Vb of the output voltage V as a target value forthe output control process for controlling the output from thehigh-frequency power supply 31 to the electrodes 21 and 22 after thesecond point of time (tb), based on the integrated value W′b detected asthe second parameter (S121). According to the present embodiment, thelarger the integrated value W′b of the heater electric power P′, thelarger the voltage value Vb of the output voltage V is set.

Even after the integrated value W′b has been calculated and the voltagevalue Vb of the output voltage V has been set, the processor 25 performsthe above PID control process for the target temperature T0 on theoutput from the heater power supply 41 to the heater 23 (S122). Afterthe voltage value Vb of the output voltage V has been set, the processor25 controls the output to the electrodes 21 and 22 in a manner to makethe output voltage V constant chronologically at the set voltage valueVb (S123). In other words, after the second point of time (tb), theconstant voltage control process is carried out at the set voltage valueVb. At this time, the treatment target is modified by the high-frequencycurrent applied thereto. Then, as with the embodiment describedhereinbefore, etc., the processor 25 determines whether or not theoutput time Q of the high-frequency electric power P is equal to orlarger than the threshold value Qth (S124). If the output time Q of thehigh-frequency electric power P is shorter than the threshold value Qth(S124—Yes), then processing goes back to S122. Then, the steps from S122are successively carried out. Therefore, until the output time Q reachesthe threshold value Qth, the processor 25 continues the constant voltagecontrol process for the set voltage value Vb on the output from thehigh-frequency power supply 31, continuously modifying the treatmenttarget with the high-frequency current applied thereto. If the outputtime Q is equal to or larger than the threshold value Qth (S124—Yes),then the processor 25 stops the output from the high-frequency powersupply 31 to the electrodes 21 and 22 (S125), as with the embodimentdescribed hereinbefore, etc.

Each of FIGS. 11 and 12 illustrates an example of chronological changesin the heater electric power P′ output from the heater power supply 41to the heater 23 in the processing sequence carried out by the processor25. FIG. 13 illustrates an example of target trajectories set for theoutput voltage V from the high-frequency power supply 31 when the heaterelectric power P′ changes chronologically as illustrated in FIG. 11.FIG. 14 illustrates an example of target trajectories set for the outputvoltage V from the high-frequency power supply 31 when the heaterelectric power P′ changes chronologically as illustrated in FIG. 12.FIG. 15 illustrates an example of chronological changes in the impedanceof the treatment target between the first point of time and the secondpoint of time. In each of FIGS. 11 through 15, a horizontal axisrepresents time t from the start, used as a reference, of the outputfrom the heater power supply 41. In each of FIGS. 11 and 12, a verticalaxis represents the heater electric power P′. In each of FIGS. 13 and14, a vertical axis represents the output voltage V from thehigh-frequency power supply 31. In FIG. 15, a vertical axis representsthe impedance Z. FIGS. 11 and 13 illustrate the chronological changes inthe above three states, i.e., tissue states, X1 through X3. In FIGS. 11and 13, the chronological changes in the state X1 are indicated by thesolid-line curve, the chronological changes in the state X2 by thedot-and-dash-line curve, and the chronological changes in the state X3by the broken-line curve. FIGS. 12 and 14 illustrate the chronologicalchanges in the above state X2 and a state X4 that is different from thestates X1 through X3. In FIGS. 12 and 14, the chronological changes inthe state X2 are indicated by the dot-and-dash-line curve, and thechronological changes in the state X4 by the solid-line curve. In thestate X4, the thermal load on the treatment target at an initial timesuch as the start of the output from the heater power supply 41 issubstantially the same as in the state X2. In the state X4, however, aliquid flows into the treatment target and nearby regions, causingdisturbance after the first point of time (ta), for example. Thedisturbance that is caused increases the thermal load on the treatmenttarget in the state X4. In FIG. 15, the chronological changes in thestate X2 are indicated by the dot-and-dash-line curve.

According to the present embodiment, since the PID control process forthe target temperature T0 is also carried out on the output from theheater power supply 41, the temperature T of the heater 23 and theheater electric power P′ change chronologically in the same manner asthe embodiment described hereinbefore, etc. Therefore, the chronologicalchanges in the heater electric power P′ in each of the states X1 throughX3 are the same as the embodiment described hereinbefore. Each of therate α of rise of the temperature T, the peak electric power P′p, theintegrated value W′ of the heater electric power P′, the time Y requiredfor the heater electric power P′ to reach the peak electric power P′p,the rate γ of increase up to the peak electric power P′p, and the rate εof reduction of the heater electric power P′ after having reached thepeak electric power P′p changes depending on the thermal load on thetreatment target in the same manner as the embodiment describedhereinbefore, etc. In each of the states X1 through X3, the heaterelectric power P′ becomes the peak electric power P′p between the firstpoint of time (ta) and the second point of time (tb).

In the state X4, until the first point of time (ta), i.e., untildisturbance is caused, the temperature T and the heater electric powerP′ change chronologically as in the state X2. Actually, the integratedvalue W′a4 of the heater electric power P′ from the start of the outputthereof to the first point of time (ta) in the state X4 is substantiallyidentical to the integrated value W′ a2 of the heater electric power P′from the start of the output thereof to the first point of time (ta) inthe state X2. However, in the state X4, disturbance is caused after thefirst point of time (ta) and before the second point of time (tb),resulting in an increase in the thermal load on the treatment target. Inthe state X4, because of the disturbance caused, the rate α of rise ofthe temperature T up to the target temperature T0 decreases after thedisturbance has been caused. In the state X4, the peak electric powerP′p increases and the time Y required for the heater electric power P′to reach the peak electric power P′p increases compared to a case whereno disturbance is caused. Actually, the peak electric power P′p4 in thestate X4 is larger than the peak electric power P′p2 in the state X2,and the time Y4 required for the heater electric power P′ to reach thepeak electric power P′p4 in the state X4 is longer than the time Y2required for the heater electric power P′ to reach the peak electricpower P′p2 in the state X2. In the state X4, the heater electric powerP′ becomes the peak electric power P′p between the first point of time(ta) and the second point of time (tb).

Since in the state X4, the peak electric power P′p increases compared tothe case where no disturbance is caused, the integrated value W′b of theheater electric power P′ from the first point of time (ta) to the secondpoint of time (tb) also increases. Actually, the integrated value W′b4of the heater electric power P′ from the first point of time (ta) to thesecond point of time (tb) in the state X4 is larger than the integratedvalue W′a2 of the heater electric power P′ from the first point of time(ta) to the second point of time (tb) in the state X2. In the state X4,the rate ε of reduction of the heater electric power P′ after havingreached the peak electric power P′p decreases and approaches zerocompared to the case where no disturbance is caused. In other words, inthe state X4, the heater electric power P′ after having reached the peakelectric power P′p decreases gradually compared to the case where nodisturbance is caused. Actually, the rate ε4 of reduction of the heaterelectric power P′ in the state X4 is smaller than the rate ε2 ofreduction of the heater electric power P′ in the state X2.

Furthermore, the larger the thermal load on the treatment target untilthe first point of time (ta), the larger the integrated value W′a of theheater electric power P′ as the first parameter. According to thepresent embodiment, the larger the integrated value W′a, the processor25 sets the rate ηb of change, i.e., the rate of increase, of the outputvoltage V from the first point of time (ta) to the second point of time(tb) to a larger value, and sets the value on the target trajectory forthe output voltage V to a larger value at each point of time from thefirst point of time (ta) to the second point of time (tb). Therefore,the larger the thermal load on the treatment target until the firstpoint of time (ta), the larger the rate ηb of change, i.e., the rate ofincrease, of the output voltage V is set, and the value on the targettrajectory where the output voltage V changes at the rate rib of changeis set to a larger value. Actually, the rate ηb1 of change in the stateX1 is smaller than the rate ηb2 of change in the state X2, and the valueon the target trajectory for the output voltage V in the state X1 issmaller than the value on the target trajectory in the state X2.Similarly, the rate ηb3 of change in the state X3 is larger than therate ηb2 of change in the state X2, and the value on the targettrajectory in the state X3 is larger than the value on the targettrajectory in the state X2. The rate ηb4 of change in the state X4 issubstantially identical to the rate ηb2 of change in the state X2, andthe target trajectories from the first point of time (ta) to the secondpoint of time (tb) are substantially identical to each other in thestates X2 and X4.

According to the present embodiment, from the first point of time (ta)to the second point of time (tb), the output from the high-frequencypower supply 31 is controlled based on the target trajectory with theset rate ηb of change. Therefore, the larger the thermal load on thetreatment target until the first point of time (ta), the higher theoutput from the high-frequency power supply 31 from the first point oftime (ta) to the second point of time (tb), resulting in a largerhigh-frequency current applied to the treatment target.

Since the output from the high-frequency power supply 31 is controlledbased on the target trajectory from the first point of time (ta) to thesecond point of time (tb), a high-frequency current is applied to thetreatment target. From the first point of time (ta) to the second pointof time (tb), the treatment target is dehydrated due to the heat causedby the high-frequency current, with the result that the impedance Z ofthe treatment target varies. According to the present embodiment, as theimpedance Z varies, the impedance Z takes a minimum value Zmin betweenthe first point of time (ta) and the second point of time (tb). At thetime the impedance Z takes the minimum value Zmin, the impedance Zswitches from a chronologically decreasing state to a chronologicallyincreasing state. In FIG. 15, only the impedance Z in the state X2 isillustrated. However, in each of the states X1, X3, and X4, theimpedance Z also takes a minimum value Zmin between the first point oftime (ta) and the second point of time (tb).

The larger the thermal load on the treatment target from the first pointof time (ta) to the second point of time (tb), the larger the integratedvalue W′b of the heater electric power P′ as the second parameter.According to the present embodiment, the larger the integrated valueW′b, the processor 25 sets the voltage value Vb of the output voltage Vafter the second point of time (tb) to a larger value. Consequently, thelarger the thermal load on the treatment target from the first point oftime (ta) to the second point of time (tb), the larger the voltage valueVb of the output voltage V in the constant voltage control process isset. Actually, the voltage value Vb1 in the state X1 is smaller than thevoltage value Vb2 in the state X2. Similarly, the voltage value Vb3 inthe state X3 is larger than the voltage value Vb2 in the state X2. Inthe state X4, the thermal load on the treatment target from the firstpoint of time (ta) to the second point of time (tb) increases due todisturbance caused. Therefore, the voltage value Vb4 in the state X4 islarger than the voltage value Vb2 in the state X2.

According to the present embodiment, after the second point of time(tb), the constant voltage control process is performed on the outputfrom the high-frequency power supply 31 based on the voltage value Vbset as the target value. Therefore, the larger the thermal load on thetreatment target from the first point of time (ta) to the second pointof time (tb), the higher the output from the high-frequency power supply31 after the second point of time (tb), resulting in a largerhigh-frequency current applied to the treatment target. The thermal loadon the treatment target increases from the first point of time (ta) tothe second point of time (tb) due to disturbance caused. Consequently,in the state X4, the output from the high-frequency power supply 31after the second point of time (tb) is high, and a large high-frequencycurrent is applied to the treatment target after the second point oftime (tb) compared to the state X2 where no disturbance occurs.

Inasmuch as the processor 25 performs its processing sequence describedhereinbefore, the present embodiment operates in the same manner andoffers the same advantages as the embodiment described hereinbefore,etc. Furthermore, according to the present embodiment, even ifdisturbance is caused after the start of the output from the heaterpower supply 41 and the thermal load on the treatment target isincreased by the disturbance, the increase in the thermal load due tothe disturbance is appropriately detected. After the second point oftime (tb), a target value and/or a target trajectory is set for theoutput control process for controlling the output from thehigh-frequency power supply 31 depending on the increase in the thermalload due to the disturbance caused. Therefore, even in the event ofdisturbance caused after the start of the output from the heater powersupply 41, an output is appropriately produced from the high-frequencypower supply 31 depending on the increase in the thermal load due to thedisturbance caused, and a high-frequency current is appropriatelyapplied to the treatment target depending on the increase in the thermalload due to the disturbance caused.

Modifications of the Second Embodiment

FIG. 16 illustrates an example of target trajectories set for the outputvoltage V from the high-frequency power supply 31 when the heaterelectric power P′ changes chronologically as illustrated in FIG. 11according to a modification. In FIG. 16, a horizontal axis representstime t from the start, used as a reference, of the output from theheater power supply 41, and a vertical axis the output voltage V. FIG.16 illustrates the target trajectories in the above three states, i.e.,tissue states, X1 through X3. In FIG. 16, the target trajectory in thestate X1 is indicated by the solid-line curve, the target trajectory inthe state X2 by the dot-and-dash-line curve, and the target trajectoryin the state X3 by the broken-line curve.

According to the present modification, at the first point of time (ta),the processor 25 sets a rate ηc of chronological change of the outputvoltage V based on the integrated value W′a. Then, the processor 25 setsa target trajectory where the output voltage V changes chronologicallyconstantly at the set rate ηc of change between the first point of time(ta) and the second point of time (tb). From the first point of time(ta) to the second point of time (tb), the output from thehigh-frequency power supply 31 is controlled to have the output voltageV vary along the target trajectory. According to the presentmodification, the larger the thermal load on the treatment target untilthe first point of time (ta), the larger the rate ηc of change is set,and the larger the value on the target trajectory is set. According tothe present modification, however, the processor 25 can set the rate ηcof change to a positive value, zero, or a negative value. For example,in the state X1 where the thermal load is small, the rate ηc1 of changeis set to a negative value. Therefore, according to the targettrajectory for the output voltage V set from the first point of time(ta) to the second point of time (tb) in the state X1, the outputvoltage V decreases chronologically at a constant rate of change, i.e.,a rate of reduction.

According to the present modification, at the second point of time (tb),the processor 25 sets a voltage value Vc of the output voltage V basedon the integrated value W′b. According to the present modification, thelarger the thermal load on the treatment target from the first point oftime (ta) to the second point of time (tb), the larger the voltage valueVc is set. After the second point of time (tb), the processor 25controls the output from the high-frequency power supply 31 based on theset voltage value Vc. According to the present modification, however,the processor 25 does not instantaneously change the output voltage V tothe set voltage value Vc at the second point of time (tb) or immediatelythereafter. According to the present modification, the processor 25controls the output from the high-frequency power supply 31 to have theoutput voltage V approach the set voltage value Vc gradually until sometime elapses from the second point of time (tb). Then, at a point oftime tc when some time has elapsed from the second point of time (tb),the processor 25 controls the output voltage V to reach the set voltagevalue Vc. After the point of time tc, the processor 25 performs aconstant voltage control process for chronologically maintaining theoutput voltage V at the set voltage value Vc.

In the embodiment described hereinbefore, the target values, i.e., ηb,ηc, etc., and/or the target trajectory from the first point of time (ta)to the second point of time (tb) is set based on the integrated valueW′a, and the target values, i.e., Vb, Vc, etc., and/or the targettrajectory after the second point of time (tb) is set based on theintegrated value W′b. However, the present disclosure is not limited tosuch details. According to a modification, the target values, i.e., ηb,ηc, etc., and/or the target trajectory from the first point of time (ta)to the second point of time (tb) is set based on the rate γ of increaseof the heater electric power P′ at the first point of time (ta).Moreover, the target values, i.e., Vb, Vc, etc., and/or the targettrajectory after the second point of time (tb) is set based on the rateε of reduction of the heater electric power P′ at the second point oftime (tb). Specifically, at the first point of time (ta), the targetvalues, i.e., ηb, ηc, etc., and/or the target trajectory from the firstpoint of time (ta) to the second point of time (tb) may be set based oneither one of the above parameters, i.e., α, P′p, Y, γ, ε, W′, etc.Furthermore, at the second point of time (tb), the target values, i.e.,Vb, Vc, etc., and/or the target trajectory after the second point oftime (tb) may be set based on either one of the above parameters, i.e.,α, P′p, Y, γ, ε, W′, etc.

In the embodiment described hereinbefore, etc., time ta at the firstpoint of time and time tb at the second point of time are of fixedvalues. However, the present disclosure is not limited to such details.According to a modification, the initial value Ze of the impedance Z isdetected at the same time as or immediately after the start of theoutput from the high-frequency power supply 31. Then, the processor 25sets the first point of time (ta) based on the detected initial value Zeof the impedance Z. According to a modification, after the first pointof time (ta), the processor 25 performs the above process of detectingthe minimum value Zmin of the impedance Z. Then, the processor 25 setsthe point of time when it detects that the impedance Z takes the minimumvalue Zmin, as the second point of time (tb). The minimum value Zmin isdetected according to a known process. The point of time when theminimum value Zmin is detected, i.e., the set second point of time (tb),is after the point of time when the impedance Z takes the minimum valueZmin.

Other Modifications

In the embodiment described hereinbefore, etc., the threshold value Qthfor the output time Q that is used to determine whether to stop theoutput from the high-frequency power supply 31 is of a fixed value Qth0.However, the present disclosure is not limited to such details.According to a modification, the processor 25 sets the threshold valueQth for the output time Q based on the detected parameter, i.e., eitherone of α, P′p, Y, γ, ε, and W′. Then, the processor 25 stops the outputfrom the high-frequency power supply 31 when a predetermined conditionbased on the set threshold value Qth is satisfied. If the magnitude ofthe detected parameter, i.e., either one of α, P′p, Y, γ, ε, and W′, isdifferent, then the time for which the output is produced from thehigh-frequency power supply 31 is different, and the time for which thehigh-frequency current is applied to the treatment target is different.The larger the thermal load on the treatment target, the larger thethreshold value Qth for the output time Q is set. Consequently, in casethe rate α of rise of the temperature T is to be detected as a parameterrelated to the temperature T, the smaller the rate α of rise, theprocessor 25 sets the threshold value Qth to a larger value.

According to a modification, the processor 25 may determine whether tostop the output from the high-frequency power supply 31 based on thethreshold value Zth for the impedance Z, instead of carrying out theprocessing of S109 or S124 that uses the threshold value Qth for theoutput time Q. According to the present modification, the processor 25may set the threshold value Zth to a fixed value Zth0 regardless of thedetected parameter, i.e., either one of α, P′p, Y, γ, ε, and W′, or maythe threshold value Zth based on the detected parameter, i.e., eitherone of α, P′p, Y, γ, ε, and W′. In case the threshold value Zth is to beset based on the parameter, i.e., either one of α, P′p, Y, γ, ε, and W′,the larger the thermal load on the treatment target, the processor 25sets the threshold value Zth to a larger value. For example, in case therate α of rise of the temperature T is to be detected as a parameterrelated to the temperature T, the smaller the rate α of rise, theprocessor 25 sets the threshold value Zth to a larger value.

According to the present modification, if the impedance Z is smallerthan the threshold value Zth, then the processor 25 continuouslyperforms a process similar to the processing of S106 or S107 or aprocess similar to the processing of S122 or S123 to continue the outputto the electrodes 21 and 22, thereby continuously modifying thetreatment target by applying the high-frequency current thereto.Therefore, until the impedance Z reaches the threshold value Zth, i.e.,until a condition based on the threshold value Zth is satisfied, theprocessor 25 continues the output from the high-frequency power supply31 to the electrodes, i.e., bipolar electrodes 21 and 22. If theimpedance Z is equal to or larger than the threshold value Zth, then theprocessor 25 performs a process similar to S110 or S125 to stop theoutput from the high-frequency power supply 31 to the electrodes 21 and22.

In the embodiment described hereinbefore, etc., the output from thehigh-frequency power supply 31 is started at the same time as orimmediately after the start of the output from the heater power supply41, and the high-frequency power supply 31 outputs the high-frequencyelectric power P before the parameter, i.e., either one of α, P′p, Y, γ,ε, and W′, is detected for the first time. However, the presentdisclosure is not limited to such details. According to a modification,the processor 25 may start the output to the electrodes 21 and 22 afterhaving started the output to the heater 23 and having detected theparameter, i.e., either one of α, P′p, Y, γ, ε, and W′, for the firsttime. In this case, the processor 25 keeps stopping the output from thehigh-frequency power supply 31, instead of performing the processing ofS102 or S112. According to the present modification, the target values,i.e., β, Va, Pa, Ia, ηa, Vst, ηb, Vb, ηc, Vc, etc., and/or the targettrajectory related to the output control process for controlling theoutput from the high-frequency power supply 31 is set based on theparameter, i.e., either one of α, P′p, Y, γ, ε, and W′. When the outputfrom the high-frequency power supply 31 is started, the output from thehigh-frequency power supply 31 is controlled based on the set targetvalues, i.e., β, Va, Pa, Ia, ηa, Vst, ηb, Vb, ηc, Vc, etc., and/or thetarget trajectory, and the treatment target is modified by thehigh-frequency current applied thereto.

In the embodiment described hereinbefore, etc., the output from thehigh-frequency power supply 31 is stopped when a predetermined conditionbased on the threshold value Qth for the output time Q or the thresholdvalue Zth for the impedance Z is satisfied. However, the presentdisclosure is not limited to such details. According to a modification,when the above predetermined condition based on the threshold value Qthfor the output time Q or the threshold value Zth for the impedance Z issatisfied, the processor 25 lowers the output from the high-frequencypower supply 31, reducing the high-frequency current flowing through thetreatment target to such an extent that the treatment target will not bemodified. According to the present modification, the processor 25 stopsthe output from the high-frequency power supply 31 upon elapse of acertain time from the reduction of the output to the electrodes 21 and22 or an operation made by the surgeon or the like.

In the embodiments described hereinbefore, etc., the energy outputsource 31 or 41 of the energy source apparatus 3 outputs high-frequencyelectric power P to the bipolar electrodes 21 and 22 thereby causing ahigh-frequency current to flow through the treatment target between thebipolar electrodes 21 and 22, and outputs heater electric power P′ tothe heater 23 thereby causing the heater 23 to generate heat. Theprocessor 25 performs the output control process on the output to theheater 23 to cause the heater 23 to reach the target temperature T0 andto maintain the heater 23 at the target temperature T0, and detects theparameter, i.e., α; P′p; Y; γ; ε; or W′ related to at least one of thetemperature T of the heater 23 and the output to the heater 23 in theoutput control process based on the target temperature T0. Then, theprocessor 25 sets at least one of the target values, i.e., β, Va, Pa,Ia, ηa, Vst, ηb, Vb, ηc, Vc, etc., and the target trajectory related tothe output control process for controlling the output to the bipolarelectrodes 21 and 22 while the treatment target is being modified by thehigh-frequency current applied thereto, based on the detected parameter,i.e., α; P′p; Y; γ; ε; or W′.

The technology disclosed herein is not limited to the embodimentsdescribed hereinbefore, but various modifications may be made thereinwithout departing from the scope of the disclosure when it is reduced topractice. The embodiments may be appropriately combined as much aspossible, and the combinations offer combined advantages. Furthermore,the embodiments include disclosures in various stages, and variousdisclosures can be extracted by appropriately combining a plurality ofcomponents that are disclosed.

One aspect of the disclosed technology is directed to an energy sourceapparatus used in a treatment tool having a heater and bipolarelectrodes. The energy source apparatus comprises an energy outputsource configured to output high-frequency electric power to the bipolarelectrodes through a first circuit. A high-frequency current flowingthrough a treatment target between the bipolar electrodes. The energyoutput source is configured to output heater electric power to theheater for generating heat through a second circuit. At least oneprocessor is configured to control the energy output source. Theprocessor is configured to control the heater for reaching a targettemperature while maintaining the heater at the target temperature. Theprocessor detects a parameter calculated based on the second circuitduring the process of controlling the heater for reaching the targettemperature and set a target value and/or a target trajectory foroutputting the high-frequency electric power based on the parameter.

The processor is configured to start outputting the high-frequencyelectric power to the bipolar electrodes after outputting the heaterelectric power and detecting the parameter. The processor controls thehigh-frequency electric power to the bipolar electrodes based on thetarget value and/or the target trajectory and modifies the treatmenttarget by applying the high-frequency current thereto. The smaller theparameter, the processor sets the target value to a larger value and/orsets at least one of a gradient of the target trajectory and a value atthe starting point of the target trajectory to a larger value. Theprocessor is configured to detect a rate of increase of the temperatureof the heater until the target temperature is reached as the parameter.The larger the parameter, the processor sets the target value to alarger value and/or sets at least one of a gradient of the targettrajectory and a value at the starting point of the target trajectory toa larger value. The processor is configured to detect at least one ofpeak electric power of the heater electric power output to the heater, atime required for the heater electric power to reach the peak electricpower, a rate of increase of the heater electric power until the peakelectric power is reached, a rate of reduction of the heater electricpower after the peak electric power is reached, and an integrated valueof the heater electric power as the parameter.

The processor is configured to set the target value and/or the targettrajectory with respect to at least one of the high-frequency electricpower output to the bipolar electrodes. The high frequency currentoutput to the bipolar electrodes, a voltage output to the bipolarelectrodes, and an impedance of the treatment target. The parameterincludes a first parameter and a second parameter. The processor isconfigured to detect the first parameter at a first point of time, todetect the second parameter at a second point of time after the firstpoint of time, and to set the target value and/or the target trajectoryfrom the first point of time to the second point of time based on thefirst parameter and set the target value and/or the target trajectoryafter the second point of time based on the second parameter. Theprocessor is configured to control the high-frequency electric power tothe bipolar electrodes based on the target value and/or the targettrajectory to modify the treatment target with the high-frequencycurrent applied thereto to thereby minimizing an impedance of thetreatment target between the first point of time and the second point oftime. The processor is configured to control the energy output sourcesuch that the larger a thermal load being applied on the treatmenttarget, the larger the high-frequency current flows through thetreatment target. The processor is configured to detect the parametercalculated based on the second circuit during the process of controllingthe heater for reaching the target temperature. The parameter is relatedto a temperature of the heater and/or an output from the heater electricpower and set the target value and/or the target trajectory foroutputting the high-frequency electric power based on the parameterwhile the treatment target is being modified by the high-frequencycurrent applied thereto.

Another aspect of the disclosed technology is directed to a treatmentsystem comprises a treatment tool having a heater and bipolar electrodesto grip a treatment target. An energy source apparatus is used toelectrically communicate with the treatment tool. The energy outputsource is configured to output high-frequency electric power to thebipolar electrodes through a first circuit. A high-frequency currentflows through the treatment target between the bipolar electrodes andthe energy output source is configured to output heater electric powerto the heater for generating heat through a second circuit. At least oneprocessor is used to control the energy output source. At least oneprocessor is configured to control the heater for reaching a targettemperature while maintaining the heater at the target temperature. Theprocessor detects a parameter calculated based on the second circuitduring the process of controlling the heater for reaching the targettemperature and set a target value and/or a target trajectory foroutputting the high-frequency electric power based on the parameter.

A further aspect of the disclosed technology is directed to a method ofoperating a treatment system having a treatment tool including a heaterand bipolar electrodes to grip a treatment target and an energy sourceapparatus used to electrically communicate with the treatment tool. Theenergy source apparatus comprises at least one processor used to controlthe energy output source by: outputting high-frequency electric power tothe bipolar electrodes through a first circuit, a high-frequency currentflowing through the treatment target between the bipolar electrodes,outputting heater electric power to the heater for generating heatthrough a second circuit, controlling the heater for reaching a targettemperature while maintaining the heater at the target temperature,detecting a parameter calculated based on the second circuit during theprocess of controlling the heater for reaching the target temperature,and setting a target value and/or a target trajectory for outputting ahigh-frequency electric power based on the parameter while the treatmenttarget is being modified by the high-frequency current applied thereto.

While various embodiments of the disclosed technology have beendescribed above, it should be understood that they have been presentedby way of example only, and not of limitation. Likewise, the variousdiagrams may depict an example schematic or other configuration for thedisclosed technology, which is done to aid in understanding the featuresand functionality that can be included in the disclosed technology. Thedisclosed technology is not restricted to the illustrated exampleschematic or configurations, but the desired features can be implementedusing a variety of alternative illustrations and configurations. Indeed,it will be apparent to one of skill in the art how alternativefunctional, logical or physical locations and configurations can beimplemented to implement the desired features of the technologydisclosed herein.

Although the disclosed technology is described above in terms of variousexemplary embodiments and implementations, it should be understood thatthe various features, aspects and functionality described in one or moreof the individual embodiments are not limited in their applicability tothe particular embodiment with which they are described, but instead canbe applied, alone or in various combinations, to one or more of theother embodiments of the disclosed technology, whether or not suchembodiments are described and whether or not such features are presentedas being a part of a described embodiment. Thus, the breadth and scopeof the technology disclosed herein should not be limited by any of theabove-described exemplary embodiments.

Terms and phrases used in this document, and variations thereof, unlessotherwise expressly stated, should be construed as open ended as opposedto limiting. As examples of the foregoing: the term “including” shouldbe read as meaning “including, without limitation” or the like; the term“example” is used to provide exemplary instances of the item indiscussion, not an exhaustive or limiting list thereof; the terms “a” or“an” should be read as meaning “at least one,” “one or more” or thelike; and adjectives such as “conventional,” “traditional,” “normal,”“standard,” “known” and terms of similar meaning should not be construedas limiting the item described to a given time period or to an itemavailable as of a given time, but instead should be read to encompassconventional, traditional, normal, or standard technologies that may beavailable or known now or at any time in the future. Likewise, wherethis document refers to technologies that would be apparent or known toone of ordinary skill in the art, such technologies encompass thoseapparent or known to the skilled artisan now or at any time in thefuture.

The presence of broadening words and phrases such as “one or more,” “atleast,” “but not limited to” or other like phrases in some instancesshall not be read to mean that the narrower case is intended or requiredin instances where such broadening phrases may be absent.

Additionally, the various embodiments set forth herein are described interms of exemplary schematics, block diagrams, and other illustrations.As will become apparent to one of ordinary skill in the art afterreading this document, the illustrated embodiments and their variousalternatives can be implemented without confinement to the illustratedexamples. For example, block diagrams and their accompanying descriptionshould not be construed as mandating a particular configuration.

What is claimed is:
 1. An energy source apparatus used in a treatmenttool having a heater and bipolar electrodes, the energy source apparatuscomprising: an energy output source configured to output high-frequencyelectric power to the bipolar electrodes through a first circuit, ahigh-frequency current flowing through a treatment target between thebipolar electrodes, and the energy output source configured to outputheater electric power to the heater for generating heat through a secondcircuit; and at least one processor configured to control the energyoutput source, wherein the processor is configured to: control theoutput heater electric power to the heater to reach a targettemperature; maintain the heater at the target temperature, detect aparameter calculated based on the second circuit during the process ofcontrolling the output heater electric power to the heater for reachingthe target temperature, and set a target value and/or a targettrajectory for outputting the high-frequency electric power through thefirst circuit based on the parameter, wherein: the smaller theparameter, the processor is configured to set the target value to alarger value and/or sets at least one of a gradient of the targettrajectory and a value at a starting point of the target trajectory to alarger value.
 2. The energy source apparatus of claim 1, wherein theprocessor is configured to start outputting the high-frequency electricpower to the bipolar electrodes after outputting the heater electricpower and detecting the parameter, control the high-frequency electricpower to the bipolar electrodes based on the target value and/or thetarget trajectory, and modify the treatment target by applying thehigh-frequency current thereto.
 3. The energy source apparatus of claim1, wherein the processor is configured to detect a rate of increase ofthe temperature of the heater until the target temperature is reached asthe parameter.
 4. The energy source apparatus of claim 1, wherein theprocessor is configured to detect at least one of peak electric power ofthe heater electric power output to the heater, a time required for theheater electric power to reach the peak electric power, a rate ofincrease of the heater electric power until the peak electric power isreached, a rate of reduction of the heater electric power after the peakelectric power is reached, and an integrated value of the heaterelectric power as the parameter.
 5. The energy source apparatus of claim1, wherein the processor is configured to set the target value and/orthe target trajectory with respect to at least one of the high-frequencyelectric power output to the bipolar electrodes, the high frequencycurrent output to the bipolar electrodes, a voltage output to thebipolar electrodes, and an impedance of the treatment target.
 6. Theenergy source apparatus of claim 1, wherein the parameter includes afirst parameter and a second parameter, the processor is configured todetect the first parameter at a first point of time and the processor isconfigured to detect the second parameter at a second point of timeafter the first point of time; and the processor is configured to setthe target value and/or the target trajectory from the first point oftime to the second point of time based on the first parameter, and setthe target value and/or the target trajectory after the second point oftime based on the second parameter.
 7. The energy source apparatus ofclaim 6, wherein the processor is configured to control thehigh-frequency electric power to the bipolar electrodes based on thetarget value and/or the target trajectory to modify the treatment targetwith the high-frequency current applied thereto to thereby minimizing animpedance of the treatment target between the first point of time andthe second point of time.
 8. The energy source apparatus of claim 1,wherein the processor is configured to control the energy output sourcesuch that the larger a thermal load being applied on the treatmenttarget, the larger the high-frequency current flows through thetreatment target.
 9. The energy source apparatus of claim 1, wherein theprocessor is configured to detect the parameter calculated based on thesecond circuit during the process of controlling the output heaterelectric power to the heater for reaching the target temperature, theparameter being related to a temperature of the heater and/or an outputfrom the heater electric power, set the target value and/or the targettrajectory for outputting the high-frequency electric power based on theparameter while the treatment target is being modified by thehigh-frequency current applied thereto.
 10. A treatment systemcomprising: a treatment tool having a heater and bipolar electrodes togrip a treatment target; and an energy source apparatus used toelectrically communicate with the treatment tool wherein an energyoutput source configured to output high-frequency electric power to thebipolar electrodes through a first circuit, a high-frequency currentflowing through the treatment target between the bipolar electrodes, andthe energy output source configured to output heater electric power tothe heater for generating heat through a second circuit, and at leastone processor used to control the energy output source, wherein the atleast one processor is configured to: control the output heater electricpower to the heater to reach a target temperature, maintain the heaterat the target temperature, detect a parameter calculated based on thesecond circuit during the process of controlling the output heaterelectric power to the heater for reaching the target temperature, andset a target value and/or a target trajectory for outputting thehigh-frequency electric power through the first circuit based on theparameter, wherein: the smaller the parameter, the processor sets thetarget value to a larger value and/or sets at least one of a gradient ofthe target trajectory and a value at a starting point of the targettrajectory to a larger value.
 11. The treatment system of claim 10,wherein the processor is configured to: start outputting thehigh-frequency electric power to the bipolar electrodes after outputtingthe heater electric power and detecting the parameter, control thehigh-frequency electric power to the bipolar electrodes based on thetarget value and/or the target trajectory, and modify the treatmenttarget by applying the high-frequency current thereto.
 12. The treatmentsystem of claim 10, wherein the smaller the parameter, the processorsets the target value to a larger value and/or sets at least one of agradient of the target trajectory and a value at the starting point ofthe target trajectory to a larger value.
 13. The treatment system ofclaim 10, wherein the larger the parameter, the processor sets thetarget value to a larger value and/or sets at least one of a gradient ofthe target trajectory and a value at the starting point of the targettrajectory to a larger value.
 14. The treatment system of claim 10,wherein the processor is configured to set the target value and/or thetarget trajectory with respect to at least one of the high-frequencyelectric power output to the bipolar electrodes, a high frequencycurrent output to the bipolar electrodes, a voltage output to thebipolar electrodes, and an impedance of the treatment target.
 15. Thetreatment system of claim 10, wherein the parameter is defined byrespective first and second parameters each of which being detected bythe processor at respective first and second point of time and whereinthe processor is configured to set the target value and/or the targettrajectory from the first point of time to the second point of timebased on the first parameter, and set the target value and/or the targettrajectory after the second point of time based on the second parameter.16. The treatment system of claim 10, wherein the processor isconfigured to detect the parameter calculated based on the secondcircuit during the process of controlling the heater for reaching thetarget temperature, the parameter being related to a temperature of theheater and/or an output from the heater electric power, set the targetvalue and/or the target trajectory for outputting the high-frequencyelectric power based on the parameter while the treatment target isbeing modified by the high-frequency current applied thereto.
 17. Amethod of operating a treatment system having a treatment tool includinga heater and bipolar electrodes to grip a treatment target and an energysource apparatus used to electrically communicate with the treatmenttool, the energy source apparatus comprising at least one processor usedto control an energy output source by: outputting high-frequencyelectric power to the bipolar electrodes through a first circuit, ahigh-frequency current flowing through the treatment target between thebipolar electrodes; outputting heater electric power to the heater forgenerating heat through a second circuit; controlling the output heaterelectric power the heater to reach a target temperature; maintaining theheater at the target temperature; detecting a parameter calculated basedon the second circuit during the process of controlling the outputheater electric power to the heater for reaching the target temperature;setting a target value and/or a target trajectory for outputting ahigh-frequency electric power based on the parameter while thehigh-frequency current is applied to and modifies the treatment target;and the smaller the parameter, setting the target value to a largervalue and/or setting at least one of a gradient of the target trajectoryand a value at a starting point of the target trajectory to a largervalue.
 18. The method of operating a treatment system of claim 17wherein the parameter is defined by respective first and secondparameters each of which being detected by the processor at respectivefirst and second point of time and wherein the processor is configuredto set the target value and/or the target trajectory from the firstpoint of time to the second point of time based on the first parameter,and set the target value and/or the target trajectory after the secondpoint of time based on the second parameter.